Electrically conductive surgical shoe-encasing cover



Aug. 15, 1967 s. A. PENCE 3,335,506

ELECTRICALLY CONDUCTIVE SURGICAL SHOE-ENCASING COVER Filed July 15, 1959 2 Sheets-Sheet l INVENTOR. -.SADON AM ES DENCE ATTORNEY Aug. 15, 1967 s. A. PENCE 3,335,506

ELECTRICALLY CONDUCTIVE SURGICAL SHOE-ENCASING COVER Filed July 15. 1959 2 Sheets-Sheet i3 INVENTOR. .SARO/V AMES PE/VCE 1477' ORA FY United States Patent 3,335,506 ELECTRICALLY (IGNDUQTIVE SURGICAL SHOE-ENCASKNG COVER Saran Andes Pence, San Rafael, Califi, assignor to Harold Zimmon, Belmont, Calir. Filed July 15, 1959, Ser. No. 827,992 18 Claims. (Cl. 36-71) This invention relates to an improved electrically conductive shoe-encasing cover for surgeons and the like. More particularly, my invention involves a sanitary cover for shoes having an electrically conductive, floor-contacting sole and means for electrically grounding the body of a person wearing the shoe cover. This application is a continuation-in-part of application Ser. No. 739,081, filed June 2, 1958, now abandoned.

Everyone has experienced electrical shocks after scuffing across a rug, or touching a door handle of a moving car, etc. These sparks are only minor unpleasantries in most instances, but in certain environments they are capable of setting off severe and disastrous explosions.

For example, although the problem has had very little publicity and laymen are not generally aware of it, doctors know that the danger of explosion is always present in a surgical operating room because anesthetic gases, such as ether, are highly explosive. The slightest electrical spark can and has caused tragic explosions. Thus, one object of my invention is to promote safety in operating rooms by preventing these sparks from occurring.

As an additional example, workmen in plants using or manufacturing explosive chemicals or gases know what can happen from one loose spark, and they are aware that such sparks can result wherever static electricity is uncontrolled. Thus, another object of my invention is to prevent charges of static electricity from building up and discharging in places where it could cause an explosion or start a fire.

The best way to prevent a spark from discharging from an object is to continually ground the object to draw off static electric charges before they can build up a potential sufi'icient to jump to another material object.

To state the problem a little more specifically, friction between two unlike material bodies, especially bodies of poor conductivity, tends to generate static electricity. The friction can be that between leather or rubber shoes and carpeted floors or plastic-tiled floors. Even friction with dry air or the rustling of ones clothing as one moves about tends to build up a static charge. So when a human body is moving about, a difference of electric potential with respect to other bodies tends to develop. If there is an insulating material (such as dry air) between two bodies at different potential levels, the charge builds up faster than it is being dissipated, until finally the dielectric strength of the insulating medium is insufficient to prevent a sudden rush of electricity across the spark gap, and there is a flash of light, indicating a very high temperature. Voltages are often in excess of 25,000 volts before the ditference in potential is sufficient to cause the spark-over.

Now, if the two bodies are connected by an electrical conductor instead of being separated by an insulator, no substantial difference in electric potential can develop between them, and there will be no sparks. My invention provides such a conductor in the form of a shoe sole that dissipates static electricity as it is generated by friction with the floor and also has a tongue-like member that can be placed in contact with the wearers body to dissipate any other charges built up on his body. In other words, he is kept at ground potential.

In addition to the above problem, my invention solves another very important problem in operating rooms, that of sanitation.

When a surgical instrument is dropped on the floor in a hospital operating room, it may not be picked up or used again until sterilized. This, even though the floors are frequently scrubbed and are apparently kept spotless, This exemplifies the care taken to keep germs from the operating table. Yet the shoes worn by doctors and nurses into the operating room inevitably carry dust and germs that are liable to get into the air in the room. Moreover, blood and other body fluids have fallen on their shoes and ruined them or at least damaged them, sometimes even getting inside the shoes where they are an annoyance at the least and, at worst, dangerous.

The real problem was that shoe covers prevented conductivity unless the entire cover was electrically conductive, which was never the case due to the expense involved and other reasons. In the past, hospitals and doctors were therefore required to choose between sanitation and the prevention of germs, and conductivity and the prevention of explosions. With my invention both problems are solved and no longer is one precaution sacrificed for another. Thus, another object of the present invention is to provide a sanitary shoe cover that completely encases the shoe and can be easily cleaned, sterilized, and re-used, yet is an excellent conductor.

My invention also solves the problem of providing a shoe cover requiring only a minimum number of sizes to fit over many sizes of shoes.

What about past attempts to meet the above problems? Some shoe attachments intended to prevent charges of static electricity from building up on the wearer caused uneven soles that tended to affect the balance and efiiciency of doctors and nurses, and to cause discomfort. Some attachments used metal conductors that extended from the shoe soles and ran up the leg of the wearer to an electrode-garter or other device around the leg. Needless to say, this was unattractive and uncomfortable and took too much time to put on and take off.

Further disadvantages of prior art attempts were the weight of the attachments, the unevenness to the wearer, and the noise of metal conductors in contact with the floor. Also, none of them provided a sanitary cover for street shoes and they could not readily be washed and sterilized.

Still another disadvantage of some prior devices was that the conductive element was located only on the heel or only on the sole. Then, when the wearer was standing on his toes, or on his heels alone, he was not conductive. My device prevents any possible period of nonconductivity while the wearer has a foot on the floor.

Other prior devices, such as typified by the Monahan Patent 2,287,744 and the Lewis et al. Patent 2,701,323

obtained conductivity without any substantial protection of the shoe or encasement of it to protect the operating room from the germs thereon.

In the present invention I provide a sanitary shoe cover that completely encases the shoe in a non-conducting cover, but which has a conducting sole and a conducting tongue connected to the sole and extending up inside the shoe cover so as to be placed in contact with the wearer, while still encased in the cover.

Other objects and advantages of my invention will become apparent from the following description. The illustrative embodiment set out in the drawings and described in detail herein is not intended to limit the scope of the invention as described in the appended claims but rather is intended to comply with 35 U.S.C. 112.

In the drawings:

FIG. 1 is a view in perspective of one form of shoe cover embodying the principles of the present invention shown prepared for the insertion of the shoe. Some portions have been broken away to show the structure better.

FIG. 2 is a view in side elevation of the cover of FIG. 1 after the shoe is put in it and the conductive tongue tucked inside the shoe and in contract with the foot of wearer. Portions of this view are broken away and shown in section.

FIG. 3 is a top plan view of a conductive sole of this invention prior to its assembly with the fabric to make the completed article shown in FIG. 1.

FIG. 4 is a fragmentary bottom plan view of the toe portion of the cover shown in FIG. 1, with portions broken away to show the construction.

FIG. 5 is a view similar to that of FIG. 4, but showing a modified structure.

FIG. 6 is an enlarged fragmentary view in side elevation and in section of the heel portion of the modified form of cover shown in FIG. 5.

FIG. 7 is an enlarged fragmentary view in side elevation and in section of the heel portion of the form of cover shown in FIG. 4.

FIG. 8 is a view generally similar to FIG. 1 of a modified form of device embodying the principles of the invention.

FIG. 9 is a view generally similar to FIG. 2 of the device of FIG. 8.

FIG. 10 is a top plan view of the cloth blank from which the cover of the FIG. 8 device is made.

FIG. 11 is a top perspective view of the shoe cover of FIG. 8 in a partially completed state during manufacture.

FIG. 12 is an enlarged top plan view of the inside heel portion of a partially made device of FIG. 8.

FIG. 13 is a further enlarged view of the conductive tongue portion shown in FIG. 12.

The shoe cover 10 of FIG. 1 has an upper side wall portion 11 of fabric, such as canvas duck or other flexible material, to which is stitched a conductive sole 12, so that it completely encases the shoe 20 (see FIG. 2). The sole 12 is made of electrically conductive material, preferably a rubber coated fabric impregnated with carbon which is commonly called conductive rubber sheeting. This sole has an integral tongue 13 made of the same conductive material and extends up inside the heel of the cover 10. The full purpose and effect of this novel structure will be explained later, but it should be emphasized even here as important in obtaining full conduction and full protection by'e'ncasement.

In the shoe cover 10, a conventional type of shoe tongue 14- is secured to the side walls 11 by stitches 15 and 16 on opposite sides of a gap 17, closing the gap. This tongue 14 is madeof the samefabric material as the upper sidewall 11. A pair of ties 18, 19 are also stitched to the side wall 11 on opposite sides of the gap 17 for tightening. the cover 10 and holding it around, a shoe 20 as by a bowknot as shown in FIG. 2. When so tightened, the cover 10 completely encloses and also fully protects the she 20.

The upper side wall 11 may be made from two pieces 21 and 22 that are identical in size and shape and are stitched together at a heel seam 23. The tongue 14 runs to the toe edge 24 and the seams 15 and 16 also hold the pieces 21 and 22 together. A fabric inner sole or lining 25 overlies the conductive sole 12 and, with it, is secured to the shoe upper 11 by suitable stitching. Two forms of this stitching are shown, one in FIG. 4 and the other in FIG. 5. In the shoe shown in FIG. 4, the lining 25 is placed over the sole 12, the lower edge 26 of the upper 11 overlies the lining, a tape reinforcement 27 covers the edge both above the edge portion 26 and below the sole 12, and then one or more lines of stitching 28 is used all around the edge, holding the parts together.

In the structure of FIGS. 5 and 6, bottom edges 30 of the upper side wall 11 are turned under and folded, and the cover is turned inside out during the sewing. Thus, the stitching 31 is not visible from the bottom, and no reinforcing tape 27 is needed.

The remainder of assembly of the cover 10 is an easy and obvious matter, except for one very novel feature: The conductive tongue 13 is folded at a heel end 32 and is then doubled back over the lining 25 and brought up inside the shoe cover 11) at the heel end.

After the bottom of the shoe cover 10 is completed, the tongue 14 is placed inside and between the two side portions 21 and 22 and the portions 21 and 22 overlay the edges of the tongue 14 almost up to the top of the upper 11. The tongue and sides are stitched together along either side. The tongue 14 is left free above the stitching to be free to flap forward and allow easy insertion of the shoe 2% The two upper sides 21, 22 are then sewn up at the heel seam 23. Then, if desired, a hem 33 of heavier material can be sewn around the free edges of the fabric. The ties 18, 19 may be attached to the two upper sides 21, 22 at any time, and in any number of ways. The drawings show them stitched toward the top of the upper 11 and back from the toe sufliciently to hold the cover 10 on the shoe 2% securely. The length of the ties 18, 19 need only be enough to allow a bowknot to be tied when the shoe 20 is in the cover 10.

The method of making my conductive cover above is set forth to give the required complete disclosure. There are other possible ways of doing it still coming within the scope of my invention.

When the cover 10 is to be used, the shoes 20 are removed and placed in the covers 11. The conductive tongue 13 is laid over the heel and into the shoe 20. Then the shoes 20 are placed once again on the wearers feet, the Shoelaces tied, then the ties 18, 19 on the cover 11 are tied, and the wearer is not conductive. Whether the doctor or nurse is wearing socks or not does not affect the conductivity, for the moisture in the socks conducts any charge in the body of the wearer to the tongue 13. This broad firm contact with the body of the wearer assures good conductivity as compared to the earlier attempts along this line.

FIGS. 8-13 show a modified and presently preferred form of the invention. Here a shoe cover 51} is again provided which completely encases the shoe 20 and again has the conductive sole 12 with its conductive tongue 13 made inside the shoe cover 51 Preferably, as shown here, the sole 12 and tongue 13 are cut as in FIG. 3 from a single piece of material and are cut on a bias. In other words, the threads of the fabric in the sole 12 lie at about 45 to the longitudinal axis. Again, the tongue 13 is doubled back on the conductive sole 12, lying above the nonconductive protective and reinforcing sole cover 51. As shown best in FIGS. 12 and 13, the portion of the tongue 13 closest to the sole 12 is protected by a pair of binding strips 52, each held by a line of stitching 53, the two stitching lines 53 and being joined by cross line 54, if desired, to permit continuous stitching. This construction not only reinforces the base of the tongue 13 but also prevents it from being accidentally cut off when seaming the heel portion of the cover to the sole 12.

The cover 50 is preferably made by attaching a single fabric sheet 55 to the sole 12 and sole cover 51. The sheet 55 may be cut approximately as shown in FIG. 10,

one edge preferably being bound by a strip 56. The sheet '55, sole cover 51 and sole 50 are sewn together simultaneously. As shown in FIG. 11, sewing may start at one end 57 of the binding strip 56, the unbound edge 58 being the one sewn to the sole 12 and sole cover 13 by stitching 59. The stitching 59 preferably extends around and wraps the edges, as shown in FIG. 11. Later this is covered by a binding strip 60 that greatly prolongs the life of the article.

As the stitching 59 continues around the sole 12 and sole cover 51, it makes an overlap, ending with the other end 61 of the binding 56 on the opposite side of the sole from the end 57 and symmetric with it.

In this structure there is nothing corresponding to the tongue 14, but instead there is a kind of wrap-around, overlap structure, with a lower front wall 62 secured to the left side of the sole and an upper front wall 63 secured to the right side. Each has a lace-like or striplike tie 64 stitched to it. When the cover 50 is loose, it is quite easy to put on a shoe 20, and when tied, the wall 63 overlies the wall 62 over the full front part of the shoe 20 to give double protection against germs from the inside and body fluids from the outside. The binding strips 52, 56 and 60 protect the edges of the materials against wear, and when the cover 50 is tied, it tightly encases the shoe 20 while still giving it conductivity via the tongue 13 inside the cover 50 and the sole 12 outside the cover 50.

In most hospitals today, there is a conductive tester which all those entering the operating room must stand on to determine if they are conductive and will pass harmles'sly through the sole of their shoe cover any electricity which is built up. When using my device, this is a matter of routine only.

After the operation of completion of whatever job it is which requires the conductive cover, the covers 10 or 50 removed. Where sterilization is required, then these are placed in the wash. In a short time the covers 10 or 50 are ready for another trip into the operating room.

My shoe cover is so easy to put on and take off that people dont mind using it. There are no wires to fool with and once the cover is on, the wearer can only tell that it is on by looking. The sole is extremely thin and the covers dont weigh over five ounces a pair.

The advances which I have made with this conductive shoe cover could be summarized as follows:

( 1) Assured conductivity.

(2) Sterilizable and sanitary. (3) Easy to use.

(4) Inexpensive to manufacture. (5) Fit many sizes.

(6 Washable.

(7) Comfortable.

To those skilled in the art to which this invention relates, many changes in construction and widely differing embodiments and applications of the invention will suggest themselves without departing from the spirit and scope of the invention. The disclosures and the description herein are purely illustrative and are not intended to be in any sense limiting.

I claim:

1. A shoe cover for surgeons and the like, including an upper fabric portion for completely enclosing a shoe and an electrically conductive sole attached to said upper portion and exposed on the bottom thereof and having a flexible electrically conductive tongue extending from the sole up inside said upper portion loose therefrom and of substantially greater height than said upper portion, so that it can be tucked over and into the covered shoe to establish electrical contact with the wearer.

2. A sanitary shoe cover comprising an upper portion completely enclosing a shoe upper, and a sole of electrically conductive carbon treated rubber sheeting with .a conductive tongue portion extending loosely inside said upper 6 portion so that it can be tucked into the shoe encased in said cover and thereby ground the wearers body.

3. A sanitary shoe cover having means for completely encasing a shoe which is on a wearers foot to keep shoeborne dirt and germs within the cover and to protect the shoe from exterior defiling matter, and a ground contacting electrically conductive sole having a tongue extending up inside shoe cover and loose with respect thereto and of sufficient length to be tucked inside said shoe.

4. A shoe cover including a fabric upper portion having two sides, a toe end and a heel end, a gap between the two sides adjacent the toe end, and a lower edge; a fabric tongue extending up from said toe end and bridging said gap and sewn to the two sides of the upper portion to approximately one-half the length of the tongue; a hem at the heel end where the two sides are joined directly to each other, so that shoe cover completely covers a shoe; an electrically conductive sole attached to said upper portion at its lower edge; a flexible electrically conductive tongue extending from the sole at the heel end up inside the upper so that it can be tucked over and into a covered shoe to establish electrical contact with the wearer; and means for holding the cover in place on the shoe.

5. A shoe cover including an upper portion having two sides and a gap between the two sides, a toe end and a heel end, a first tongue bridging said gap, extending from said toe end, and sewn to the two sides of the upper portion to approximately one-half the length of the tongue, an electrically conductive sole attached to said upper portion at its edges, an inner sole of the upper material lining the conductive sole, a second tongue portion extending out from the sole and up inside the upper, so that it may be tucked over and into the shoe, to have contact with a wearer, and a means for holding the cover in place on the shoe so that it substantially completely encloses said shoe.

6. A sanitary cover worn over a shoe including in combination a cloth upper portion, adapted to fully envelop the shoe to keep dirt and germs within, a ground contacting electrically conductive sole, and means for connecting said sole to the body of wearer.

7. A sanitary shoe cover including a cloth upper portion substantially longer and higher than wearers shoe, means for closing said cover to fully envelop the shoe, and a sole portion of electrically conductive rubber with an extending tongue for electrically connecting said sole to the wearer.

8. A shoe cover comprising an electrically nonconductive fabric upper portion made loosely to permit free insertion of a shoe; means for tightening said upper portion snugly around a shoe, fully enclosing said shoe; a sole of electrically conductive rubber sheeting with a conductive portion which extends up loosely inside the upper portion of the cover and adapted to be inserted into the shoe into contact with wearers body, thereby conductively connecting wearer to the sole and ground.

9. The cover of claim 8 wherein said sheeting has a fabric reinforcement of woven material and is cut on a bias with respect thereto.

10. A washable sanitary and electrically grounding shoe cover for surgeons and the like, including in combination a flexible electrically conducting sheet cut to provide an outersole and a long tongue extending from the heel end of said outersole; a fabric innersole overlying said outersole; a sidewall of fabric made in one piece and sewn to said innersole and outersole around the edge thereof with a long overlap from one side of a toe portion thereof to the other side to provide overlapping upper and lower front wall portions covering the front of a shoe with a double thickness and unattached to each other except where they are attached to said soles; and means for fastening said overlapping wall portions together snugly around a shoe on a wearer to completely encase the shoe and the wearers foot, said long tongue extending up inside said sidewall so that it can be tucked into the shoe in contact with the wearers foot.

11. The shoe cover of claim wherein said lastnamed means for fastening comprises a pair of tie strips, one stitched to each said front wall portion.

12. The shoe cover of claim 10 wherein the portion of said tongue adjoining said outersole has its edges bound by fabric strips stitched thereto.

13. The shoe cover of claim 10 wherein the sewn edge of said innersole, outersole, and sidewall is bound with a fabric strip and so are the unsewn edges of said sidewall.

14. The shoe cover of claim 10 wherein said tongue and innersole sheet has reinforcing woven material and is cut on a bias with respect thereto.

15. A garment adapted to be worn over the human foot and to envelop it completely comprising a sole portion containing a water insensitive, conductive material throughout; attached to edges of said sole portion an upper portion being a sheet of flexible material the ends of which are in overlapping position adapted to coact in spreading apart to admit the foot of the wearer and to envelop it completely; attached to the said sole a flexible ribbon containing a water insensitive, conductive material and having a freely moveable length sufficient to allow next-to-skin contact with the wearer to effect the electrical grounding of the wearer to avoid accumulation of static electricity; and means to fasten the garment to the wearer.

16. A garment in accordance with claim in which the said ribbon is attached to the sole at its heel portion.

17. A garment, adapted to be worn over the human foot and to envelop it completely, comprising an upper section encasing a portion of the leg; means for grounding the person of the wearer comprising a conductive sole and connected to said conductive sole a conductive strip having a freely moveable length suflicient to allow nextto-skin contact of the wearer to effect the grounding of the wearer and prevent accumulation of static electricity, said leg encasing portion being affixed to the said sole portion in an overlapping position maintained throughout the height of said garment; and means to fasten the garment to the wearer.

18. A claim in accordance with claim 17 in which said conductive strip is fixed to the said conductive sole portion at the heel section of said sole portion.

References Cited UNITED STATES PATENTS 2,287,744 6/ 1942 Monahan 3172 2,701,323 2/1955 Lewis 3l72 2,745,041 5/1956 Price 317--2 PATRICK D. LAWSON, Primary Examiner.

SAMUEL BERNSTEIN, EDWARD V. BENHAM,

DAVID J. WILLIAMOWSKY, Examiners.

J. D. KALLAM, R. C. KAMP, F. J. COHEN,

Assistant Examiners.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,335,506 August 15, 1967 Saron Ames Pence It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Eolumn 4, line 23, for "overlay" read overlap 47, strike out "not"; column 5, line 55, for "of", first line occurrence, read or line 37, after "50'' insert are same line 37, for "then these are" read they are then Signed and sealed this 30th day of July 1968.

(SEAL) Attest:

EDWARD J. BRENNER Eifward M. Fletcher, Jr.

Attesting Officer Commissioner of Patents 

1. A SHOE COVER FOR SURGEONS AND THE LIKE, INCLUDING AN UPPER FABRIC PORTION FOR COMPLETELY ENCLOSING A SHOE AND AN ELECTRICALLY CONDUCTIVE SOLE ATTACHED TO SAID UPPER PORTION AND EXPOSED ON THE BOTTOM THEREOF AND HAVING A FLEXIBLE ELECTRICALLY CONDUCTIVE TONGUE EXTENDING FROM THE SOLE UP INSIDE SAID UPPER PORTION LOOSE THEREFROM AND OF SUBSTANTIALLY GREATER HEIGHT THAN SAID UPPER PORTION, SO THAT IT CAN BE TUCKED OVER AND INTO THE COVERED SHOE TO ESTABLISH ELECTRICAL CONTACT WITH THE WEARER. 